For Joyce Mallon, the births of her three children are "a miracle." Conceived on Oct. 26, 2007, in a lab by in vitro fertilization, the embryos were implanted into her uterus at two-year intervals, giving her and her husband three children conceived on the same day but born years apart.
"They are my Tripblings!! Triplets via conception, siblings by actual birth," she wrote in an email sent to CNN. "I believe our story to be an exciting and intriguing one, that NO ONE in the U.S. (to my knowledge), has any claim to."
Fertility experts say while the Mallon births are exciting, they're not a first. With better freezing techniques, many babies have been born by doing what the Mallons did: creating a group of embryos, using some to start one pregnancy, and then freezing the rest for future pregnancies. Three babies born this way aren't triplets, but rather three genetically unique siblings conceived on the same day and born years apart.
"I can think off the top of my head of several couples who've done this,'" said Dr. Daniel Shapiro, medical director of Reproductive Biology Associates in Atlanta. "This isn't new."
Shapiro added that it is, however, exciting. He says more and more couples are using frozen embryos. Using embryos from the freezer is less expensive than harvesting a woman's eggs anew each time a couple wants another baby, and it's also less invasive for the mother, since harvesting eggs from a woman's ovaries requires a medical procedure and sedation or anesthesia.
In 2007, after the Mallons discovered they were unable to conceive a child on their own, they went to the Advanced Reproductive Care Center in Irving, Texas, which helped them create eight viable embryos. When the embryos were five days old, doctors implanted two of them into Joyce Mallon's uterus and froze the rest. About nine months later, Julianna Grace was born.
The Mallons then had six frozen embryos left. Less than a year after Juliana's birth, doctors implanted two of them, but Mallon miscarried.
Less than two months later, doctors implanted two of the remaining four frozen embryos. This time it worked, and AnnaSophia Grace was born May 28, 2010.
A year and a half later, doctors thawed and implanted the final two embryos, resulting in baby Andrew Gracin last month.
The Mallons gave the three babies similar names since they were conceived at the same time, each with an "Ann" sound.
"Becoming a mother, is the most important thing I will ever do in my lifetime, and I am PROUD of the way in which my Tripblings were conceived," Mallon wrote.
Shapiro estimates that about 25 percent of babies are conceived through frozen embryos, and the rest through fresh.
Dr. Jamie Grifo, program director of the New York University Fertility Center, said it is unusual to have enough viable frozen embryos to have three babies, but it's still not unheard of.
"There are plenty of babies born this way," he said.
Mallon said she considers the frozen embryos to be human beings, and mourns the loss of the five embryos that did not result in a baby.
"I grieve for them every single day," she told CNN.
When Andrew was born, she said she cried for two hours, relieved that the siblings created at the same time had been reunited.
"All I could say was, 'We waited so long for you,' " she said. "We were back together as a family."
CNN Medical Producers Caitlin Hagan and Miriam Falco contributed to this report.